From the human point of view this is true. However, the present is a record of the past. Physical laws work forwards as well as backwards. There are only two things that point time's arrow: entropy, and the expansion of the universe. Account for those and you can model backwards. The future, however, is a little trickier. It is totally statistical. There, you are right, the future cannot be predicted acurately. I know all this may seem semantic, and irrelevant to the point psydreal is trying to make, but we most always keep in mind that humans are a tiny little part of reality. Any elevation of our own inate limitations to universal principles dangerously limits our already minute ability to understand the universe around us and our place within it.